The RaceQuip® 9161 series Chevron-5 multi-layer SFI-5 racecar driver's fire suit pants are made up of an outer layer of durable Nomex® and a soft, comfortable and lightweight Nomex® liner with Chevron pattern box quilting. High quality two-way zipper installed with a double overlap for a more secure front opening. Exceeds SFI 3.2A/5 specs. Note that sometimes these materials are referred to as "fireproof", but actually all auto racing safety gear is "fire retardant".